The overall goal of this research career award is to contribute to the professional, academic and research development of Dr. Evaline A. Alessandrini. By combining a focus on ambulatory and emergency services, a strong commitment to vulnerable pediatric populations and expertise in pediatric emergency care, Dr. Alessandrini hopes to make significant contributions to the field of pediatric outcomes and health services research. She plans to achieve these goals via a comprehensive, interdisciplinary program that includes a preceptorship with J. Sanford Schwartz, M.D., and completion of formal training and independent study in health services research, public policy and advanced research methodology. Dr. Alessandrini hopes to use this award to establish herself as an academic leader in the area of pediatric outcomes and health services research. Equitable access to primary health care is a social goal that has proved difficult to achieve in the U.S. Despite attempts to improve access to health care through Medicaid and other programs, poverty among children continues to be associated with decreased physician contacts, inability to identify a medical home and increased reliance on the emergency department (ED). The candidate's previous research demonstrated that Medicaid managed care did not alter ED use or immunization status in a cohort of newborns compared to infants enrolled in fee-for- service Medicaid. She now hopes to develop strong health services research skills to generate the knowledge required to more effectively improve ambulatory care for indigent children. The specific aims of the current study are three-fold. First, clinical prediction rules will be developed to identify Medicaid enrolled newborns at risk for delayed immunization and reliance on the ED for ambulatory care. Next, the clinical prediction rules will be prospectively validated in different populations, assuring that they are usable and generalized tools. Finally, the accuracy of administrative claims data will be assessed by comparison to medical record review. The broad goals of the research project are to delineate factors that place poor children at risk for inadequate primary care health services and to identify these children so that effective interventions may be made.